Resolving simultaneous triggersIt seems then that DM interpretation allowing, the following order applies : (1) Attack kills 7 minions and damages non-minion (2) RoK triggers x 7 and resolves essentially as a rider attached to the end of the attack (3) RoK damage can therefore only by applied to the remaining adjacent non-minion, and (4) Monk teleports x 7 times, resolving as 7 separate free actions following the attack.

Resolving simultaneous triggersIt is indeed unclear, but thanks for the interpretation. A logical "order of death" would indeed seem to make it so that the order would be "damage is dealt to adjacent enemy , then teleport" x 7. However with it ruled this way, assuming the DM doesn't interfere with free actions, you could do as follows: (1) Enemy #1 dies, deal damage to adjacent enemy, teleport, (2) Enemy #2 dies, deal damage to adjacent enemy (after teleport), teleport, (3) Enemy #3 dies, deal damage to adjacent enemy (at new teleport position), and so on. Thanks for your thoughts!